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<h1>vexa</h1><p><span class="helptopic">Convert augmented skew-symmetric matrix to vector</span></p><p>
<strong>v</strong> = <span style="color:red">vexa</span>(<strong>s</strong>) is the vector which has the corresponding augmented skew-symmetric
matrix <strong>s</strong>.

</p>
<p>
<strong>v</strong> is 1x3 in the case that <strong>s</strong> (3x3) =

</p>
<pre style="width: 90%%;" class="examples">
|&nbsp;&nbsp;0&nbsp;&nbsp;-v3&nbsp;&nbsp;v1&nbsp;|
|&nbsp;v3&nbsp;&nbsp;&nbsp;&nbsp;0&nbsp;&nbsp;v2&nbsp;|
|&nbsp;&nbsp;0&nbsp;&nbsp;&nbsp;&nbsp;0&nbsp;&nbsp;&nbsp;0&nbsp;|
</pre>
<p>
<strong>v</strong> is 1x6 in the case that <strong>s</strong> (6x6) =

</p>
<pre style="width: 90%%;" class="examples">
|&nbsp;&nbsp;0&nbsp;&nbsp;-v6&nbsp;&nbsp;&nbsp;v5&nbsp;&nbsp;v1&nbsp;|
|&nbsp;v6&nbsp;&nbsp;&nbsp;&nbsp;0&nbsp;&nbsp;-v4&nbsp;&nbsp;v2&nbsp;|
|-v5&nbsp;&nbsp;&nbsp;v4&nbsp;&nbsp;&nbsp;&nbsp;0&nbsp;&nbsp;v3&nbsp;|
|&nbsp;&nbsp;0&nbsp;&nbsp;&nbsp;&nbsp;0&nbsp;&nbsp;&nbsp;&nbsp;0&nbsp;&nbsp;&nbsp;0&nbsp;|
</pre>
<h2>Notes</h2>
<ul>
  <li>This is the inverse of the function SKEWA().</li>
  <li>The matrices are the generator matrices for se(2) and se(3).</li>
  <li>This function maps se(2) and se(3) to twist vectors.</li>
</ul>
<h2>References</h2>
<ul>
  <li>Robotics, Vision & Control: Second Edition, Chap 2,
P. Corke, Springer 2016.</li>
</ul>
<h2>See also</h2>
<p>
<a href="skewa.html">skewa</a>, <a href="vex.html">vex</a>, <a href="Twist.html">Twist</a></p>
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